The Northampton Street Bridge is a bridge that crosses the Delaware River, connecting Easton, Pennsylvania and Phillipsburg, New Jersey, United States. It is maintained by the Delaware River Joint Toll Bridge Commission despite not being a toll bridge. It is known locally as the "Free Bridge" thus distinguishing it from the Easton-Phillipsburg Toll Bridge just upstream to the north. The crossing was first a ferry crossing run by David Martin, beginning in 1739. The original wooden bridge opened on October 14, 1806. The original bridge was designed and built by Timothy Palmer, one of the most famous bridge builders of his time. Palmer's covered bridge at Easton endured many floods and storms while other bridges fell.

However, by the late nineteenth century, when horse-drawn streetcars were replaced by trolley cars, the old wooden bridge could no longer handle the demands of traffic and a new structure was erected in 1895. The new bridge was designed by James Madison Porter III, an alumnus of nearby Lafayette College and later a professor of civil engineering there. Porter hailed from a family long prominent in Easton and Pennsylvania history.

Tolls were charged until 1921, when the DRJTBC bought it from the Delaware Bridge Company.[1]

The Northampton Street Bridge sustained major damage during Hurricane Diane when floodwaters, 44 feet (13 m) above normal water level, topped the roadway of the bridge on August 19, 1955. Although the bridge withstood this topping, when large floating wooden pieces of the Portland-Columbia covered bridge which was washed out in the same flood waters were jammed against the bridge, the center of the span was torn away.

Repairs carried out by Bethlehem Steel over the next two years made the bridge usable but the flood damage left a readily apparent sag in the center span that remains today.[2]

Another series of improvements were completed in the summer of 2002 and included structural steel repair and replacement, painting, and the replacement and installation of sidewalk decking and new pedestrian railings.

The bridge is currently posted for a three-ton weight limit and a fifteen mile per hour speed limit.